1. Field of the Invention
The invention relates to a method for the production of a sound insulation molding with mass and spring, such a sound insulation molding, and the use thereof.
2. Related Technology
From EP 0 882 561 A1 there is known a method for the production of a sound insulation molding with mass and spring, with which both the mass and the spring are produced on the basis of the same material, namely polyurethane. For the formation of a mass, reaction substances and fillers are sprayed or injected into a mold and brought to reaction, whereby by means of a die there is attained a forming of the mass as a mass layer. Foam is then formed in the same mold, as a spring on the mass, and this by means of a second molding through which the mass layer is foamed on the back.
With the known approach a continuous mass layer with essentially uniform thickness is obtained, whereby with appropriate configuration the side which is to be seen can in particular have the shape of individual profiles in the manner of grooves or ribs. The spring, or foam layer, can likewise be shaped. Through this the molding can be adapted to certain developments of a surface to be sound insulated, to which the molding is to be attached.
The outlay of materials required in the production of the mass or heavy layer is substantial and thus cost-intensive. In addition, a somewhat economic production is possible only in the case of large quantities. Typical moldings of the described type are used in vehicles, in particular cars. Cars are offered, with the same bodywork construction, with very different engines, so that in the configuration of the molding and thereby in particular the mass or heavy layer the most unfavorable constellation of an engine as a sound generator and surface to be sound damped by the molding must be taken into account.